Antigen-Induced Airway Obstruction and the Influence of Vagus Blockade

Islam²,

Ulmer³

1976

Self Cite

Respiratory hypersensitivity and systemic effects after local application of Ascaris suum extract on the segmental bronchus and after its intravenous infusion are studied on four boxer dogs. Influence of ipsilateral vagus blockade on the respiratory hyperreactivity after intrabronchial application of ascaris was also investigated on the same dogs. Ascaris extract was applied in liquid form directly through a catheter into the right segmental bronchus. Egg albumin was applied in the same way for control. Local application of ascaris was repeated after ipsilateral central vagus blockade and once more after recovering vagus effect by lavage. At the end of the experiments ascaris extract was infused intravenously. The parameters studied were: ΔP_oes mm Hg/100 ml TV (as a measurement of flow resistance in the airways), respiratory rates, arterial blood gases and pH, heart frequency, systemic blood pressure and histamine concentration per milliliter of plasma. All the animals presented a remarkable respiratory distress with local ascaris application, which could be clearly avoided with ipsilateral central vagus blockade. This respiratory hyperreacitvity was not observed after intravenous infusion of ascaris extract, but a significant systemic effect, which was not the case after local application, could be observed.

Section: Methodsmentioning

confidence: 99%

“…Asthma models in dogs and monkeys have been produced by exposing the animals to aerosol challenge with Ascaris suum extract [2, II,13]. The effect of central vagus blockade in experimental asthma in dogs was also studied by using different methods of central vagus blockade [1.…”

mentioning

confidence: 99%

Effect of Ascaris Extract Applied Intravenously, on Segment Bronchus and the Influence of Ipsilateral Vagus Blockade

Islam²,

Ulmer³

1976

Self Cite

“…Dogs have proved to be useful models for studying asthma because of their bronchospastic response to inhaled antigen [Booth et al, 1970;Dabi and Gold, 1975;Gold et al, 1977;Zimmermann et al, 1976b].…”

Section: Introductionmentioning

confidence: 99%

Effect of Intravenous Histamine, Allergen <i>(Ascaris suum</i> Extract) and Compound 48/80 and Inhaled Allergen-Aerosol on Bronchoconstriction and Histamine Release

Ulmer²

1981

Self Cite

The effect of a histamine releaser (48/80), an antigen (Ascaris suum extract) and of exogenous histamine infusion on antigen aerosol-induced bronchoconstriction was investigated in 24 mongrel dogs. During these substance infusions, the high values of arterial plasma histamine did not correlate with the degree of bronchoconstriction. Further, a severe bronchoconstriction with a relatively low arterial plasma histamine concentration was observed during antigen inhalation. During substance inhalation, a high local concentration of histamine is assumed to explain the increased bronchial ‘sensitivity’ to actual plasma levels of histamine. Also, the responsiveness of the bronchial tree to antigen aerosol was observed to be reduced 90 min after induction of a strong histamine release. The importance of histamine in the first phase of immediate hypersensitivity is discussed.

“…Stimulation of receptors of the airways of man, dogs and monkeys by antigens, physical or pharmacological agents results in bronchoconstriction [Empey et al, 1976;DeKock et al, 1966;Widdicombe and Ster ling, 1970], Dogs with immediate-type respiratory responses to nematode antigens have pro vided a particularly useful subject for the study of reflex mechanisms involved in air way responses [Patterson et al, 1974;Gold et ai, 1972a, b;Zimmermann et al, 1976aZimmermann et al, , b, 1978a,…”

mentioning

confidence: 99%

The Role of Upper Airways in Antigen-Induced Bronchoconstriction

Walkenhorst²,

Ulmer³

1979

Self Cite

The bronchoconstrictor effect of antigen was tested in 15 dogs. The upper and the lower airways were sequently exposed through a specially confected endotracheal tube. The antigen was also generally administered through a mouth mask. Bronchoconstriction was induced after each kind of exposure. The results argue for reflex bronchoconstriction. The sensory receptors localized in the upper part of the airways are responsible for about 50% of antigen-induced bronchoconstriction. The decrease of PO₂a was less marked following Ascaris suum extract aerosol administration to the upper part of the airways. Control measurements demonstrated the reproducibility of antigen-induced bronchoconstriction.